EP4568084A1

EP4568084A1 - Resolver rotor and resolver

Info

Publication number: EP4568084A1
Application number: EP22954089.3A
Authority: EP
Inventors: Yosuke Otsubo; Takashi Endo; Hideki Hisada; Kazuo Aoki; Kotaro Kobayashi
Original assignee: Toshiba Corp; Toshiba Infrastructure Systems and Solutions Corp
Current assignee: Toshiba Corp
Priority date: 2022-08-03
Filing date: 2022-12-19
Publication date: 2025-06-11
Also published as: WO2024029101A1; JP7342215B1; US20240413725A1; CN118556362A; JP2024021347A

Abstract

According to an embodiment, a resolver rotor (100) includes: a resolver rotor core (110); and a resolver rotor core holder (120) that constrains the resolver rotor core (110) to a rotor shaft (11a) in a circumferential direction and an axial direction. The resolver rotor core holder (120) includes: an annular flat plate portion (121); a first constraining portion (122) that holds a relative position of the resolver rotor core holder (120) to the rotor shaft (11a), and holds an angle of the resolver rotor core (110) in the circumferential direction relative to the rotor shaft (11a); a second constraining portion (123) that holds a relative position of the resolver rotor core holder (120) to the rotor shaft (11a); and a third constraining portion that holds a relative position of the resolver rotor core (110) in the axial direction to the rotor shaft (11a). The resolver rotor core (110) includes a radially inside recessed portion for engagement with the first constraining portion (122).

Description

FIELD

The present invention relates to a resolver rotor and a resolver.

BACKGROUND

In the rotary electric machines, a rotation angle sensor has been widely used to detect the rotation angle of a rotary shaft. A resolver, which is one of the rotation angle sensors, is composed of, for example, a resolver rotor fixed to a rotary shaft of a rotary electric machine to rotate together with the rotary shaft, and a resolver stator arranged to face the outer circumference of the resolver rotor. Such a resolver measures a variation in the facing distance (gap) between the resolver rotor and the resolver stator and detects the rotation angle of the rotary shaft.

PRIOR ART DOCUMENT

PATENT DOCUMENT

Patent Document 1: Japanese Patent No. 4628904

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

In order to improve the detection accuracy of the rotation angle, the resolver rotor needs to inhibit the displacement of the resolver rotor itself relative to the rotary shaft as much as possible. For example, a method has conventionally been employed in which the resolver rotor is positioned in the circumferential direction by forming a key groove in the rotary shaft and providing a key shape in the resolver rotor. Further, for example, after the resolver rotor is clearance fitted to the rotary shaft, a member such as a collar is press-fitted into the rotary shaft to press the resolver rotor in the axial direction, thereby making it possible to inhibit the displacement of the resolver rotor in the axial direction. In addition, the displacements of the resolver rotor in the circumferential direction and the radial direction can also be inhibited with the frictional force generated between the member such as a collar and the resolver rotor.
On the other hand, when the resolver rotor is pressed in the axial direction by a predetermined member press-fitted into the rotary shaft to thereby be positioned, it is necessary to appropriately adjust the load (pressing force) to be applied for inhibiting the displacement of the resolver rotor relative to the rotary shaft.
An object of the present invention is to provide a resolver rotor and a resolver that enable displacement inhibition and load adjustment.

MEANS FOR SOLVING THE PROBLEMS

To attain the above-described object, a resolver rotor according to an embodiment of the present invention is a resolver rotor of a resolver that detects a rotation angle of a rotating part of a target rotary electric machine, the resolver rotor including: a resolver rotor core that is mounted on a radially outer side of a rotor shaft of the target rotary electric machine and includes a plurality of resolver rotor plates stacked in an axial direction of the rotor shaft; and a resolver rotor core holder that holds relative positions of the resolver rotor core in a circumferential direction and the axial direction to the rotor shaft, in which the resolver rotor core holder includes: an annular flat plate portion; a first constraining portion that is formed to protrude from an inner edge side of the flat plate portion with being sandwiched between two groove portions formed in the inner edge side of the flat plate portion, holds a relative position of the resolver rotor core holder to the rotor shaft, and holds an angle of the resolver rotor core in the circumferential direction relative to the rotor shaft; a second constraining portion that is formed to protrude from an inner edge side of the flat plate portion with being sandwiched between two groove portions formed in the inner edge side of the flat plate portion and holds a relative position of the resolver rotor core holder to the rotor shaft; and a third constraining portion that is formed on an inner edge side of the flat plate portion and holds a relative position of the resolver rotor core in the axial direction to the rotor shaft, and the resolver rotor core includes a radially inside recessed portion formed in an inner edge portion to engage with the first constraining portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a sectional longitudinal view illustrating an example where a resolver according to a first embodiment is installed in a rotary electric machine
Fig. 2 is a perspective view illustrating a configuration of a resolver rotor according to the first embodiment
Fig. 3 is a sectional longitudinal view illustrating the configuration of the resolver rotor according to the first embodiment, viewed in the A-A arrow direction in Fig. 2
Fig. 4 is a front view illustrating a configuration of a rotor core holder of the resolver rotor according to the first embodiment, viewed in the B-B arrow direction in Fig. 3
Fig. 5 is a partial plan view illustrating a state of a first constraining portion after the rotor core holder of the resolver rotor according to the first embodiment is punched out
Fig. 6 is a perspective view illustrating the first constraining portion in a state where the rotor core holder of the resolver rotor according to the first embodiment is installed
Fig. 7 is a partial plan view illustrating a state of a second constraining portion after the rotor core holder of the resolver rotor according to the first embodiment is punched out
Fig. 8 is a perspective view illustrating the second constraining portion of the resolver rotor core holder in a state where the rotor core holder of the resolver rotor according to the first embodiment is installed
Fig. 9 is a perspective view illustrating a third constraining portion of the resolver rotor core holder of the resolver rotor according to the first embodiment
Fig. 10 is a front view illustrating a configuration of a rotor core holder of a resolver rotor according to a second embodiment
Fig. 11 is a perspective view illustrating a fourth constraining portion of the rotor core holder of the resolver rotor according to the second embodiment
Fig. 12 is a sectional longitudinal view illustrating the relationship between a first example of the fourth constraining portion of the rotor core holder of the resolver rotor according to the second embodiment and a constraining hole formed in a resolver rotor core
Fig. 13 is a sectional longitudinal view illustrating the relationship between a second example of the fourth constraining portion of the rotor core holder of the resolver rotor according to the second embodiment and the constraining hole formed in the resolver rotor core
Fig. 14 is a sectional longitudinal view illustrating a modified example of the second example of the fourth constraining portion of the rotor core holder of the resolver rotor according to the second embodiment

DETAILED DESCRIPTION

There will be explained a resolver rotor according to an embodiment of the present invention with reference to the drawings below. Here, common reference numerals and symbols are given to parts that are the same as or similar to each other, and redundant explanations are omitted.

[First embodiment]

Fig. 1 is a sectional longitudinal view illustrating an example where a resolver 20 according to a first embodiment is installed in a rotary electric machine 10.
The rotary electric machine 10 includes a rotor 11 being a rotating part that rotates around a rotation axis, a stator 12, a frame 13, and the resolver 20.
The rotor 11 includes a rotor shaft 11a extending in the rotation axis direction, a rotor core 11b provided on the radially outer side of the rotor shaft 11a, and two end plates 11c that are provided on both sides of the rotor core 11b in the axial direction to constrain the rotor core 11b in the axial direction. The rotor shaft 11a, the rotor core 11b, and the two end plates 11c rotate as a single unit around a rotation axis C of the rotor shaft. In the following explanation, the direction along the rotation axis C of the rotor shaft 11a is defined as the axial direction, and the rotation direction of the rotor shaft 11a is defined as the circumferential direction. Further, the direction perpendicular to the axial direction and the circumferential direction is defined as the radial direction, and the side approaching an axial center C in the radial direction is defined as the inner side, and the side moving away from the axial center C in the radial direction is defined as the outer side.
The stator 12 includes a stator core 12a arranged on the radially outer side of the rotor core 11b, and a stator winding 12b passing through the stator core 12a.
The frame 13 houses the rotor core 11b, the stator 12, and the like.
The resolver 20 is mostly housed within the frame 13 and includes a resolver stator 21 and a resolver rotor 100.
The resolver rotor 100, which will be explained in detail with reference to Fig. 2 and subsequent drawings, is mounted on the rotor shaft 11a and rotates together with the rotor shaft 11a.
The resolver stator 21 is provided on the radially outer side of the resolver rotor 100 with a gap provided therebetween, and is supported by the frame 13 or a stationary part connected thereto. The resolver stator 21 includes a resolver stator core 21a and a resolver stator winding (not illustrated) wound around the resolver stator core 21a.
Fig. 2 is a perspective view illustrating a configuration of the resolver rotor 100 according to the first embodiment. Further, Fig. 3 is a sectional longitudinal view illustrating the configuration of the resolver rotor according to the first embodiment, viewed in the A-A arrow direction in Fig. 2.
The resolver rotor 100 includes a resolver rotor core 110 including a plurality of resolver rotor plates 111, each of which is made of, for example, an electromagnetic steel sheet, stacked in the axial direction, and a resolver rotor core holder 120 that constrains the resolver rotor core 110.
The resolver rotor core 110 is formed by stacking a plurality of plate-shaped members (to be referred to as the resolver rotor plate 111 below). The resolver rotor plates 111 are formed in a manner that steel sheets are each formed into an annular shape having the same shape and size, and the resolver rotor plates 111 are connected together in the axial direction by, for example, caulking or another means to form a single unit.
Each of the resolver rotor plates 111 has a circular center opening 111h formed in the center and having the same diameter. The resolver rotor plates 111 are stacked with the center openings 111h concentrically communicating with each other. The resolver rotor plates 111 are stacked in this manner and the center openings 111h are communicated, and thereby, a through hole 110h is created in the center of the resolver rotor core 110. The center opening 111h is formed so that the diameter (inside diameter) of the center opening 111h is set to a size that enables a clearance fit at an outer circumferential portion of the rotor shaft 11a. Thereby, the resolver rotor core 110 can be mounted on the rotor shaft 11a with the through hole 110h clearance-fitted to the outer circumference of the rotor shaft 11a.
Further, the contour of the outer circumferential edge of the resolver rotor plate 111 (to be referred to as an outer circumferential shape below) is formed into a noncircular shape that varies a gap with the resolver stator 21. For example, the resolver rotor plate 111 has an outer circumferential shape in which a plurality of wide-width portions 111w having the same curvature, which is larger than the curvature of an inner circumferential portion of the facing resolver stator 21, are lined up in the circumferential direction. The wide-width portions 111w that are adjacent to each other in the circumferential direction are continuous with each narrow-width portion 111n provided therebetween. The narrow-width portion 111n is a portion in which the outer circumferential shape of the resolver rotor plate 111 is concavely depressed, and that is formed by the adjacent wide-width portions 111w, and has the minimum diameter across the outer circumferential shape. That is, the resolver rotor plate 111 has a planar shape in which the wide-width portion 111w and the narrow-width portion 111n are alternately continuous, and each outer circumferential shape of the wide-width portion 111w and each outer circumferential shape of the narrow-width portion 111n are alternately continuous at the outer circumferential edge.
In this embodiment, as one example, four wide-width portions 111w and four narrow-width portions 111n are each provided, and are arranged point-symmetrically about the axial center C. However, the number of wide-width portions 111w and the number of narrow-width portions 111n are not particularly limited.
In the resolver 20 (Fig. 1), the resolver rotor core 110 is rotated relative to the resolver stator 21, thereby making it possible to vary the gap therebetween periodically. At this time, the rotation angle of the rotor shaft 11a with the resolver rotor core 110 mounted thereon is detected based on the variation in the gap. For example, when a magnetic field is formed by applying a current to a coil wound around the resolver stator 21 while the rotor shaft 11a is rotating, the resolver rotor core 110 rotates in this magnetic field. Therefore, by detecting the state where a magnetic flux changes at that time, the rotation angle of the rotor shaft 11a can be detected. The resolver 20 composed of the resolver rotor core 110 and the resolver stator 21 outputs a rotation angle signal corresponding to the rotation angle of the resolver rotor that rotates with the rotation of the rotor shaft 11a to a control device (not illustrated). Thereby, the control device performs rotation control of the rotary electric machine based on the output rotation angle signal.
The resolver rotor core 110 is supported by a seat surface 11s (Fig. 3) of the rotor shaft 11a in the axial direction, with the through hole 110h clearance-fitted to the outer circumference of the rotor shaft 11a. As illustrated in Fig. 3, the seat surface 11s is a stepped portion made by a diameter difference between a large diameter portion and a small diameter portion at the outer circumferential portion of the rotor shaft 11a, and is a continuous annular flat portion in the circumferential direction. In the example illustrated in Fig. 3, the resolver rotor core 110 has an axial end surface (lower surface in Fig. 3, to be referred to as a first end surface blow) 110e thereof butted against the seat surface 11s, and the first end surface 110e is in surface contact with the seat surface 11s. In this case, the resolver rotor core 110 has the first end surface 110e butted against the seat surface 11s with the rotor shaft 11a inserted through the through hole 110h from above in the axial direction.
With the first end surface 110e being in surface contact with the seat surface 11s in this manner, the resolver rotor core 110 is supported by the resolver rotor core holder 120 relative to the rotor shaft 11a.
The resolver rotor core holder 120 is an annular member that can be press-fitted into the rotor shaft 11a, and positions and fixes the resolver rotor core 110 in the axial direction with sandwiching the resolver rotor core 110 with the seat surface 11s. The resolver rotor core holder 120 is formed of a raw material with a linear coefficient of expansion similar to that of the rotor shaft 11a, for example, in order to inhibit changes in the fixed state of the resolver rotor core 110 caused by temperature changes. As long as this is satisfied, a specific raw material is not particularly limited.
Fig. 4 is a front view illustrating a configuration of the rotor core holder 120 of the resolver rotor according to the first embodiment, viewed in the B-B arrow direction in Fig. 3. That is, Fig. 4 illustrates a mapped shape of the rotor core holder 120 on a virtual plane in the B-B arrow direction.
As illustrated in Fig. 4, the resolver rotor core holder 120 includes an annular flat plate portion 121 and three types of constraining portions provided on the inner edge 121h side of the flat plate portion 121, namely, a first constraining portion 122, second constraining portions 123, and third constraining portions 124.
The flat plate portion 121 extends along the other end surface (to be referred to as a second end surface below) 110f of the resolver rotor core 110 in the axial direction. The second end surface 110f is a surface on the side opposite to the first end surface 110e in the axial direction, and is an upper surface in the example illustrated in Fig. 3.
The flat plate portion 121 comes into contact with the second end surface 110f in a state where the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a to position and fix the resolver rotor core 110. In this state, the contour of the outer circumferential edge (outer circumferential shape) of the flat plate portion 121 is a noncircular shape that is one size smaller than the outer circumferential shape of the resolver rotor core 110. This prevents the outer circumferential edge of the flat plate portion 121 from protruding from the outer circumferential edge of the resolver rotor core 110, and the magnetic flux change detected by the resolver, that is, the effect on the detection accuracy of the rotation angle of the rotor shaft 11a is suppressed.
As illustrated in Fig. 4, the flat plate portion 121 includes narrow-width portions 121n and wide-width portions 121w. The narrow-width portion 121n is a portion having the narrowest width when viewed from an outer circumferential surface 121c (Fig. 3) of the flat plate portion 121 in the direction normal to the outer circumferential surface 121c inwardly. The normal direction corresponds to the radial direction. The outer circumferential surface 121c of the flat plate portion 121 is a surface portion that connects the outer circumferential edge of a first surface 121a and the outer circumferential edge of a second surface 121b. The wide-width portion 121w is a portion wider in width than the narrow-width portion 121n. Here, the first surface 121a and the second surface 121b are end surfaces at both ends in the axial direction respectively, and the second surface 121b is a surface that comes into contact with the second end surface 110f of the resolver rotor core 110.
The wide-width portions 121w each have an outer circumferential shape that is curved in the circumferential direction with the same curvature, which is larger than the curvature of the wide-width portion 111w of the resolver rotor plate 111. The wide-width portions 121w that are adjacent to each other in the circumferential direction are continuous with each narrow-width portion 121n provided therebetween. The narrow-width portion 121n is a portion in which the outer circumferential shape of the flat plate portion 121 is concavely depressed, and that is formed by the adjacent wide-width portions 121w, and has the minimum diameter across the outer circumferential shape. That is, the flat plate portion 121 has a planar shape in which the wide-width portion 121w and the narrow-width portion 121n are alternately continuous. In this embodiment, as one example, four wide-width portions 121w and four narrow-width portions 121n are each provided, which is the same number as those of the resolver rotor plate 111, and are arranged point-symmetrically about the axial center C. However, the number of wide-width portions 121w and the number of narrow-width portions 121n are not particularly limited and do not need to match the number of those of the resolver rotor plate 111.
As described above, the resolver rotor core holder 120 includes the single first constraining portion 122, the three second constraining portions 123, and the eight third constraining portions, each of which is formed as a constraining portion. However, the number of constraining portions is not limited to these.
The first constraining portion 122 is provided based on the center angle in the circumferential direction of one of the four wide-width portions 111w set as the center. The first constraining portion 122 has a function of holding the relative position between the first constraining portion 122 itself and the rotor shaft 11a, and a function of constraining the resolver rotor core 110 in the circumferential direction.
The second constraining portions 123 each are provided based on the center angle in the circumferential direction of one of the other three of the four wide-width portions 111w, where the first constraining portion 12 is not provided, set as the center. The second constraining portion 123 has a function of holding the relative position between the second constraining portion 122 itself and the rotor shaft 11a.
The third constraining portion 124 has a function of constraining the resolver rotor core 110 in the axial direction. The third constraining portion 124 is arranged on both sides of the first constraining portion 122 and both sides of each of the three second constraining portions 123 in the circumferential direction, and the third constraining portions 124 are arranged symmetrically to each other with the first constraining portion 122 and each of the three second constraining portions 123 sandwiched therebetween at intervals on a virtual plane. Incidentally, in Fig. 4, the respective third constraining portions 124 extend toward the first constraining portion 122 and the three second constraining portions 123 respectively, but may also extend in opposite directions as long as they are symmetrically arranged.
When each of the first constraining portion 122 and the three second constraining portions 123 and the two third constraining portions 124 arranged on both sides of each constraining portion are a set, each set is arranged at intervals from each other in the circumferential direction. Further, four sets are arranged in accordance with the magnetic pole arrangement of the resolver 20, in other words, for each pole of the resolver rotor core 110.
Hereinafter, these constraining portions will be explained with reference to the respective drawings.
Fig. 5 is a partial plan view illustrating a state of the first constraining portion 122 after the rotor core holder 120 of the resolver rotor 100 according to the first embodiment is punched out. Further, Fig. 6 is a perspective view illustrating the first constraining portion 122 in a state where the rotor core holder 120 of the resolver rotor 100 according to the first embodiment is installed.
Fig. 5 illustrates a state of the rotor core holder 120 after being punched out, that is, a state where surfaces of respective portions of the rotor core holder 120 are on the same plane. In Fig. 5, a virtual inscribed circle including the inner edge 121h of the first surface 121a (Fig. 3) of the flat plate portion 121 is illustrated as a virtual circle Ci. Incidentally, in Fig. 6, the rotor core holder 120, which is in close contact with the second end surface 110f of the resolver rotor core 110, is illustrated separated from the second end surface 110f for convenience of explanation.
The first constraining portion 122 includes an extension portion 122a, two claw portions 122b, and a protruding-shape tongue portion 122c.
The extension portion 122a is sandwiched between two groove portions 121f formed in the inner edge 121h side of the flat plate portion 121. In the state illustrated in Fig. 5, the extension portion 122a is formed to protrude from the virtual circle Ci in the direction of the rotation axis C (Fig. 2), namely, inward in the radial direction.
The two claw portions 122b are each formed to have an acute angle shape at the tip of the extension portion 122a in the circumferential direction of the extension portion 122a, namely, on both sides of the extension portion 122a in the width direction. In the state illustrated in FIG. 5, the tips of the two claw portions 122b each protrude inward in the radial direction so as to be inside the virtual circle Ci.
The protruding-shape tongue portion 122c is sandwiched between the two claw portions 122b, protrudes from the virtual circle Ci in the direction of a cutting step, and is bent toward the resolver rotor core 110 side to engage with a radially inside recessed portion 110a formed in the resolver rotor core 110, as will be described later with reference to Fig. 6.
Branching portions 122g where the protruding-shape tongue portion 122c branches off from the respective claw portions 122b are each formed so that their radial positions ensure a sufficient distance from the inner edge 121h of the flat plate portion 121, which is a distance from the the inner edge 121h to the outer edge in the radial direction, so as to prevent the bent protruding-shape tongue portion 122c from coming into contact with the rotor shaft 11a (see Fig. 4). This is to prevent the decrease in pressing force of the claw portions 122b toward the rotor shaft 11a, which is caused by the protruding-shape tongue portion 122c coming into contact with the rotor shaft 11a.
Each portion of the first constraining portion 122 is elastically deformable starting from a first bending portion 122x that bends toward the first surface 121a side of the flat plate portion 121. Here, the first bending portion 122x is a portion between branching portions of the two groove portions 122f. As a result, each portion of the first constraining portion 122 is elastically deformed from the outer circumferential surface 121c of the wide-width portion 111w in the inward normal direction of the outer circumferential surface 121c, in brief, inward in the radial direction, starting from the first bending portion 122x. That is, the first constraining portion 122 functions as a spring piece.
As illustrated in Fig. 6, the first constraining portion 122 includes the two claw portions 122b that are in contact with an outer circumferential surface S2 of the rotor shaft 11a. The claw portion 122b is a radial tip portion (extending end portion) at the first constraining portion 122. When the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a, the claw portions 122b come into contact with the outer circumferential surface S2, and thereby, the first constraining portion 122 is pressed from the outer circumferential surface S2 to be elastically deformed relative to the flat plate portion 121 so as to warp outward. Then, with the resolver rotor core holder 120 positioning and fixing the resolver rotor core 110, in other words, with the flat plate portion 121 being in contact with the second end surface 110f of the resolver rotor core 110, the claw portions 122b press the outer circumferential surface S2 with the restoring force of elastic deformation of the first constraining portion 122. Thereby, the first constraining portion 122 supports the resolver rotor core holder 120 (in brief, the flat plate portion 121) in the radial direction and the axial direction relative to the rotor shaft 11a, and positions and fixes it.
As the contact mode between the claw portions 122b and the outer circumferential surface S2 is closer to a point contact, it becomes possible to intensively apply a pressing force to the outer circumferential surface S2 from the claw portions 122b. Therefore, in order to more firmly position the resolver rotor core holder 120 relative to the rotor shaft 11a, it is preferable that the claw portions 122b should make a line contact or a point contact with the outer circumferential surface S2 rather than making a surface contact. From this point of view, in this embodiment, the claw portions 122b each make substantially a point contact with the outer circumferential surface S2 at their two points.
At this time, the claw portions 122b press the outer circumferential surface S2 of the rotor shaft 11a with the restoring force of elastic deformation and this restoring force absorbs the load (pressing force) in the axial direction generated by the claw portions 122b being elastically deformed to inhibit deformation such as twisting of the flat plate portion 121.
As a result, the first constraining portion 122 is to rotate with the rotor shaft 11a integrally in a concentric state.
Incidentally, the pressing by the claw portions 112 can be adjusted by adjusting the elasticity of the elastic deformation by the length between the first bending portion 122x and each of the claw portions 122b, or by the thickness of the flat plate if the resolver rotor core holder 120 is punched out from a flat plate having a uniform thickness, or by the position of the branching portion 122g, namely, the width of the claw portion 122b, or the like.
As illustrated in FIG. 6, the radially inside recessed portion 110a is formed at the through hole 110h of the resolver rotor core 110, namely, at the inner edge in the radial direction, at a predetermined depth from the second end surface 110f toward the first end surface 110e.
When the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a, the protruding-shape tongue portion 122c is inserted into the radially inside recessed portion 110a without coming into contact with the outer circumferential surface S2 of the rotor shaft 11a.
The width of the radially inside recessed portion 110a in the circumferential direction is set so that the protruding-shape tongue portion 122c can be inserted thereinto and a gap is as small as possible.
As a result, the resolver rotor core 110 is constrained by the protruding-shape tongue portion 122c of the first constraining portion 122 that rotates with the rotor shaft 11a integrally, and the angular position with the rotor shaft 11a does not shift in the circumferential direction. That is, the resolver rotor core 110 is constrained in the circumferential direction by the protruding-shape tongue portion 122c of the first constraining portion 122.
Fig. 7 is a partial plan view illustrating a state of the second constraining portion 123 after the rotor core holder 120 of the resolver rotor 100 according to the first embodiment is punched out. Further, Fig. 8 is a perspective view illustrating the second constraining portion 123 of the resolver rotor core holder 120 in a state where the rotor core holder 120 of the resolver rotor 100 according to the first embodiment is installed.
The second constraining portion 123 includes an extension portion 123a and two claw portions 123b.
The extension portion 123a is sandwiched between two groove portions 123g formed in the inner edge 121h side of the flat plate portion 121. A concave portion 123c is formed at the tip of the extension portion on the radially inner side, resulting in that the two claw portions 123b are formed. In the state illustrated in FIG. 7, the tips of the two claw portions 123b protrude inward in the radial direction so as to be inside the virtual circle Ci.
When the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a, the claw portions 122b come into contact with the outer circumferential surface S2, and thereby, the second constraining portion 123 is pressed from the outer circumferential surface S2 to be elastically deformed relative to the flat plate portion 121 so as to warp outward. Then, with the resolver rotor core holder 120 positioning and fixing the resolver rotor core 110, in other words, with the flat plate portion 121 being in contact with the second end surface 110f of the resolver rotor core 110, the claw portions 123b press the outer circumferential surface S2 with the restoring force of elastic deformation of the first constraining portion 122. Thereby, the second constraining portion 123 supports the resolver rotor core holder 120 in the radial direction, the circumferential direction, and the axial direction relative to the rotor shaft 11a, and positions and fixes it. Regarding these points, the second constraining portion 123 is the same as the first constraining portion 122.
Here, in a state where the claw portions 123b are in contact with the outer circumferential surface S2, the concave portion 123c is formed to have a shape that provides a gap between it and the outer circumferential surface S2, resulting in that the concave portion 123c does not come into contact with the outer circumferential surface S2. At this time, the claw portions 123b press the outer circumferential surface S2 of the rotor shaft 11a with the restoring force of elastic deformation, and this restoring force absorbs the load (pressing force) in the axial direction generated by the claw portions 123b being elastically deformed to inhibit deformation such as twisting of the flat plate portion 121. As a result, the second constraining portion 123 reliably constrains the resolver rotor core holder 120 in the radial direction, the circumferential direction, and the axial direction relative to the rotor shaft 11a.
Incidentally, the pressing by the claw portions 123b can be adjusted by adjusting the elasticity of the elastic deformation by the length between the groove portion 123g and the claw portion 123b, the shape or dimensions of the concave portion 123c that determine the shape • width of the claw portions 123b, or the like.
Fig. 9 is a perspective view illustrating the third constraining portion 124 of the resolver rotor core holder 120 of the resolver rotor 100 according to the first embodiment.
The third constraining portion 124 is a plate formed by punching out a portion of the flat plate portion 121 in the vicinity of the inner edge 121h. When viewed from the direction illustrated in Fig. 4, the third constraining portion 124 extends from the flat plate portion 121 along the circumferential direction of the surface S2 with a gap provided between it and the surface S2 of the rotor shaft 11a. The third constraining portion 124 includes a base end portion 124a and a contact portion 124b.
The base end portion 124a is a stepped portion formed so as to approach the second end surface 110f of the resolver rotor core 110 in the direction in which the third constraining portion 124 extends.
A surface of the contact portion 124b that faces the second end surface 110f of the resolver rotor core 110 comes into contact with the second end surface 110f of the resolver rotor core 110. That is, the third constraining portion 124 is formed as a spring piece that allows the contact portion 124b to be elastically deformed relative to the base end portion 124a.
When the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a, the contact portion 124b is pressed from the second end surface 110f of the resolver rotor core 110 by coming into contact with the second end surface 110f, and is elastically deformed relative to the base end portion 124a so as to warp upward. Conversely, the contact portion 124b of the third constraining portion 124, which is a portion extending from the flat plate portion 121, presses the second end surface 110f of the resolver rotor core 110 with the restoring force of elastic deformation while being in contact with the second end surface 110f. As a result, the contact portion 124b presses the resolver rotor core 110 toward a seat surface S1 of the rotor shaft 11a. That is, in this state, the resolver rotor core holder 120 sandwiches the resolver rotor core 110 with the seat surface S1, to position and fix it in the axial direction. Further, the resolver rotor core holder 120 sandwiches the resolver rotor core 110 with the seat surface S1 in the axial direction, and thereby constrains the resolver rotor core 110 planarly, namely, in the radial direction and the axial direction, by the frictional force with the contact portion 124b.
Incidentally, the pressing by the contact portion 124b can be adjusted by adjusting the elasticity of the elastic deformation by the shape or dimensions of the base end portion 124a, the width and length of the contact portion 124b, or the like.
As explained above, according to this embodiment, the resolver rotor core holder 120 includes the first constraining portion 122 and the second constraining portions 122, thereby making it possible to position and fix the resolver rotor core holder 120 in the axial direction, the radial direction, and the circumferential direction relative to the rotor shaft 11a.
Further, the claw portions 122b of the first constraining portion 122 of the resolver rotor core holder 120 are fitted into the radially inside recessed portion 110a formed in the resolver rotor core 110, and thereby the resolver rotor core 110 is positioned and fixed in the circumferential direction. Further, the third constraining portion 124 of the resolver rotor core holder 120 sandwiches the resolver rotor core 110 between the resolver rotor core holder 120 and the seat surface S1, thereby making it possible to position and fix the resolver rotor core 110 in the axial direction.
As above, the resolver rotor core holder 120, which is positioned and fixed to the rotor shaft 11a, constrains the resolver rotor core 110, thereby enabling displacement inhibition and load adjustment.

[Second embodiment]

Fig. 10 is a front view illustrating a configuration of a rotor core holder 120a of a resolver rotor according to a second embodiment.
This embodiment is a modification of the first embodiment. In this embodiment, the resolver rotor core holder 120a includes four second constraining portions 123, six third constraining portions 124, and two fourth constraining portions 125.
The second constraining portion 123 has the same configuration and shape as the second constraining portion 123 in the first embodiment. The second constraining portions 123 are each arranged so as to have a circumferential center portion thereof located at the circumferential center of the wide-width portion 121W on a virtual plane. In place of the first constraining portion 122 and the three second constraining portions 123 in the first embodiment, in this embodiment, the resolver rotor core holder 120a is constrained to the rotor shaft 11a in the radial direction, the circumferential direction, and the axial direction by the four second constraining portions 123. That is, the resolver rotor core holder 120a and the rotor shaft 11a are in a state of being coupled in the radial direction, the circumferential direction, and the axial direction.
The two fourth constraining portions 125 are arranged on both sides of one of the four second constraining portions 123, at the same positions as the third constraining portions 124 in the first embodiment.
The third constraining portions 124 are arranged at the same positions as the third constraining portions 124 in the first embodiment, in a manner to sandwich each of the other three second constraining portions 123 that are not sandwiched by the fourth constraining portions 125.
When each of the four second constraining portions 123 and the two third constraining portions 124 or the two fourth constraining portions 125 arranged on both sides of each of the four second constraining portions 123 are a set, each set is arranged at intervals from each other in the circumferential direction. Further, four sets are arranged in accordance with the magnetic pole arrangement of the resolver 20, in other words, for each pole of the resolver rotor core 110.
Hereinafter, the fourth constraining portions 125, which are different from the first embodiment, will be explained, and the second constraining portions 123 and the third constraining portions 124 are not explained because they are the same as those in the first embodiment.
Fig. 11 is a perspective view illustrating the fourth constraining portion 125 of the rotor core holder 120a of the resolver rotor 100 according to the second embodiment. Incidentally, in Fig. 11, the rotor core holder 120, which is in close contact with the second end surface 110f of the resolver rotor core 110, is illustrated separated from the second end surface 110f for convenience of explanation.
The fourth constraining portion 125 is a plate formed by punching out a portion of the flat plate portion 121 in the vicinity of the inner edge 121h. When viewed from the direction illustrated in Fig. 10, the fourth constraining portion 125 extends from the flat plate portion 121 along the circumferential direction of the surface S2 with a gap provided between it and the surface S2 of the rotor shaft 11a. The fourth constraining portion 125 includes a base end portion 125a, a contact portion 125b, a bent portion 125c, and an insertion portion 125d.
The base end portion 125a is a stepped portion formed so as to approach the second end surface 110f of the resolver rotor core 110 in the direction in which the fourth constraining portion 125 extends.
A surface of the contact portion 125b that faces the second end surface 110f of the resolver rotor core 110 comes into contact with the second end surface 110f of the resolver rotor core 110. That is, the fourth constraining portion 125 is formed as a spring piece that allows the contact portion 125b to be elastically deformed relative to the base end portion 125a.
Incidentally, the pressing by the contact portion 125b can be adjusted by adjusting the elasticity of the elastic deformation by the shape or dimensions of the base end portion 125a, the width and length of the contact portion 125b, or the like.
The bent portion 125c is a portion that is bent 90 degrees toward the second end surface 110f side of the resolver rotor core 110 in the direction in which the contact portion 125b extends.
The insertion portion 125d is a portion formed by the portion extending from the contact portion 125b being turned in direction by the bent portion 125c and extending perpendicularly to the second end surface 110f of the resolver rotor core 110.
The resolver rotor core 110 has constraining holes 110b formed at positions corresponding to the insertion portions 125d of the two fourth constraining portions 125, into which the insertion portions 125d can be inserted.
Fig. 12 is a sectional longitudinal view illustrating the relationship between a first example of the fourth constraining portion 125 of the rotor core holder 120a of the resolver rotor 100 according to the second embodiment and the constraining hole 110b formed in the resolver rotor core 110. That is, Fig. 12 is a longitudinal cross-sectional view along the direction in which the fourth constraining portion 125 extends.
The constraining hole 110b in the resolver rotor core 110 is formed by constraining holes 111b formed in the respective resolver rotor plates 111 stacked in the axial direction communicating with each other.
The insertion portion 125d is a portion extending from the contact portion 125b and turned in direction 90 degrees by the bent portion 125c. Here, the contact portion 125b needs to come into contact with the second end surface 110f of the resolver rotor core 110. Therefore, for the resolver rotor plate 111 corresponding to the portion of the bent portion 125c and the resolver rotor plate 111 forming the depth for the curvature radius of the bent portion 125c from the second end surface 110f of the resolver rotor core 110, the constraining holes 111b are widened and formed to prevent interference between the bent portion 125c and the resolver rotor plate 111.
The insertion portion 125d comes into close contact with constraining side surfaces 111c of the constraining holes 111b in the resolver rotor plates 111 located away from the second end surface 110f of the resolver rotor core 110, namely, located closer to the first end surface 110e.
When the resolver rotor core 110 attempts to turn in the circumferential direction, the insertion portion 125d is pressed by the constraining side surfaces 111c of the constraining holes 111b, and is elastically deformed relative to the bent portion 125c so as to warp in the circumferential direction. Conversely, the insertion portion 125d, which is the portion extending from the contact portion 125b, presses the constraining side surfaces 111c by the restoring force of elastic deformation while being in contact with the constraining side surfaces 111c of the respective resolver rotor plates 111 of the resolver rotor core 110. As a result, the contact portion 125b constrains the resolver rotor core 110 in the circumferential direction.
Incidentally, the pressing by the insertion portion 125d can be adjusted by adjusting the elasticity of the elastic deformation by the curvature radius of the bent portion 125c, the width and length of the insertion portion 125d, or the like.
Fig. 13 is a sectional longitudinal view illustrating the relationship between a second example of the fourth constraining portion 125 of the rotor core holder 120a of the resolver rotor 100 according to the second embodiment and the constraining hole 110b formed in the resolver rotor core 110. That is, Fig. 13 is a longitudinal cross-sectional view along the direction in which the fourth constraining portion 125 extends.
This second example includes a bent portion 125g different from the bent portion 125c in the first example.
The bent portion 125g is that a portion extending from the contact portion 125b is once bent so as to move away from the second end surface 110f of the resolver rotor core 110, and then is bent toward the second end surface 110f of the resolver rotor core 110. Thereby, the insertion portion 125d connected to the bent portion 125g is formed so as to be perpendicular to the contact portion 125b.
This configuration prevents the bent portion 125g from being located inside the resolver rotor core 110, namely, being located on the first end surface 110e side rather than the second end surface 110f of the resolver rotor core 110. That is, only the insertion portion 125d is housed in the constraining hole 110b of the resolver rotor core 110. As a result, the positions of the constraining side surfaces 111c of the constraining holes 111b of the respective resolver rotor plates 111 all can be the same.
Fig. 14 is a sectional longitudinal view illustrating a modified example of the second example of the fourth constraining portion of the rotor core holder of the resolver rotor according to the second embodiment.
In this modified example, in a state before the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a, the bent portion 125g is formed so that an angle Θ between the insertion portion 125d connected to the bent portion 125g and the contact portion 125b is an angle smaller than 90 degrees. As a result, in a state before the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a, the insertion portion 125d is shaped to be on the inner side relative to the constraining side surfaces 111c of the constraining holes 111b of the respective resolver rotor plates 111, that is, it is shaped to interfere with the respective resolver rotor plates 111.
At the tip of the insertion portion 125d, a guiding portion 125e is provided. The guiding portion 125e serves as a guide for insertion into the constraining hole 110b when the resolver rotor core holder 120 is press-fitted into the rotor shaft 11a, because the insertion portion 125d is inclined inward by more than 90 degrees, to thus deviate from an insertion position into the constraining hole 110b if the insertion portion 125d remains as it is.
In this modified example formed in this manner, in a state after press-fitting of the resolver rotor core holder 120, the bent portion 125g is already elastically deformed, and thus the insertion portion 125d presses the constraining side surfaces 111c of the constraining holes 111b of the respective resolver rotor plates 111 with the restoring force of elastic deformation. This allows the contact portion 125b to further ensure a circumferential constraining force for the resolver rotor core 110.
According to the embodiments described above, it is possible to provide a resolver rotor and a resolver that enable displacement inhibition and load adjustment.

[Other embodiments]

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Further, the features of the embodiments may be combined. The embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

EXPLANATION OF REFERENCE SIGNS

10...rotary electric machine, 11...rotor, 11a...rotor shaft, 11b...rotor core, 11c...end plate, 11s...seat surface, 12..stator, 12a..stator core, 12b...stator winding, 13...frame, 20...resolver, 21...resolver stator, 100...resolver rotor, 110...resolver rotor core, 110a...radially inside recessed portion, 110b...constraining hole, 110e...first end surface, 110f...second end surface, 110h...through hole, 111...resolver rotor plate, 111a...radially inside recessed portion, 111b...constraining hole, 111c...constraining side surface, 111h...center opening, 111n...narrow-width portion, 111w...wide-width portion, 120, 120a...resolver rotor core holder, 121...flat plate portion, 121a...first surface, 121b...second surface, 121f, 121g...groove portion, 121h...inner edge, 121k...outer edge, 121n...narrow-width portion, 121w...wide-width portion, 122...first constraining portion, 122a...extension portion, 122b...claw portion, 122c...protruding-shape tongue portion, 122g...branching portion, 122x...first bending portion, 123...second constraining portion, 123a...extension portion, 123b...claw portion, 123c...concave portion, 124...third constraining portion, 124a...base end portion, 124b...contact portion, 125... fourth constraining portion, 125a...base end portion, 125b...contact portion, 125c...bent portion, 125d...insertion portion, 125e...guiding portion, 125g...bent portion, C...rotation axis, S1...seat surface, S2...outer circumferential surface

Claims

A resolver rotor being a resolver rotor of a resolver that detects a rotation angle of a rotating part of a target rotary electric machine, the resolver rotor comprising:
a resolver rotor core that is mounted on a radially outer side of a rotor shaft of the target rotary electric machine and includes a plurality of resolver rotor plates stacked in an axial direction of the rotor shaft; and

a resolver rotor core holder that holds relative positions of the resolver rotor core in a circumferential direction and the axial direction to the rotor shaft, wherein

the resolver rotor core holder includes:
an annular flat plate portion;

a first constraining portion that is formed to protrude from an inner edge side of the flat plate portion with being sandwiched between two groove portions formed in the inner edge side of the flat plate portion, holds a relative position of the resolver rotor core holder to the rotor shaft, and holds an angle of the resolver rotor core in the circumferential direction relative to the rotor shaft;

a second constraining portion that is formed to protrude from an inner edge side of the flat plate portion with being sandwiched between two groove portions formed in the inner edge side of the flat plate portion and holds a relative position of the resolver rotor core holder to the rotor shaft; and

a third constraining portion that is formed on an inner edge side of the flat plate portion and holds a relative position of the resolver rotor core in the axial direction to the rotor shaft, and

the resolver rotor core includes a radially inside recessed portion formed in an inner edge portion to engage with the first constraining portion.
The resolver rotor according to claim 1, wherein
the first constraining portion includes:
two claw portions that are provided on both sides of the protruding portion in the circumferential direction and hold a relative portion of the resolver rotor core holder to the rotor shaft; and

a protruding-shape tongue portion that is sandwiched between the two claw portions and is bent to have a tip thereof engage with the radially inside recessed portion, and

in a state where the resolver rotor core holder is installed in the rotor shaft, the two claw portions are pressed against the rotor shaft by elastic force of the protruding portion.
The resolver rotor according to claim 1, wherein
the third constraining portion has a stepped base end portion formed at a connection portion with the flat plate portion to approach the side of the resolver rotor core.
The resolver rotor according to claim 1, wherein
at the flat plate portion, a wide-width portion whose distance from an outer edge of the flat plate portion to the center of rotation of the rotating part is large and a narrow-width portion whose distance from the outer edge of the flat plate portion to the center of rotation of the rotating part is small are alternately formed,

the first constraining portion and the second constraining portion are arranged at the circumferential center of each of the wide-width portions, and

the third constraining portion is arranged on the side of the narrow-width portion adjacent to the first constraining portion or the second constraining portion.
A resolver rotor being a resolver rotor of a resolver that detects a rotation angle of a rotating part of a target rotary electric machine, the resolver rotor comprising:
a resolver rotor core that is mounted on a radially outer side of a rotor shaft of the target rotary electric machine and includes a plurality of resolver rotor plates stacked in an axial direction of the rotor shaft; and

a resolver rotor core holder that holds relative positions of the resolver rotor core in a circumferential direction and the axial direction to the rotor shaft, wherein

the resolver rotor core holder includes:
an annular flat plate portion;

a second constraining portion that is formed to protrude from an inner edge side of the flat plate portion with being sandwiched between two groove portions formed in the inner edge side of the flat plate portion and holds a relative position of the resolver rotor core holder to the rotor shaft; and

a fourth constraining portion that is formed on an inner edge side of the flat plate portion and holds a relative position of the resolver rotor core in the axial direction to the rotor shaft and holds an angle of the resolver rotor core in the circumferential direction relative to the rotor shaft, and

the resolver rotor core includes a constraining hole formed to engage with the fourth constraining portion.
The resolver rotor according to claim 5, wherein
the fourth constraining portion has a stepped base end portion formed at a connection portion with the flat plate portion to approach the side of the resolver rotor core, and further has an insertion portion formed at a tip portion thereof to engage with the constraining hole.
The resolver rotor according to claim 5, wherein
a convex portion whose distance from an outer edge of the flat plate portion to the center of rotation of the rotating part is large and a concave portion whose distance from the outer edge of the flat plate portion to the center of rotation of the rotating part is small are alternately formed, and thereby a wide-width portion and a narrow-width portion are formed alternately at the flat plate portion,

the second constraining portion is arranged at the circumferential center of each of the wide-width portions, and

the fourth constraining portion is arranged on the side of the narrow-width portion adjacent to the second constraining portion.
The resolver rotor according to claim 1 or claim 5, wherein
the second constraining portion includes:
two claw portions that are provided on both sides of the protruding portion in the circumferential direction and hold a relative portion of the resolver rotor core holder to the rotor shaft; and

in a state where the resolver rotor core holder is installed in the rotor shaft, the two claw portions are pressed against the rotor shaft by elastic force of the protruding portion.
A resolver, comprising:
the resolver rotor according to claim 1 or claim 5; and

a resolver stator including: a cylindrical resolver core arranged at a radially outer side of the resolver rotor core of the resolver rotor with a gap provided therebetween; and a resolver winding wound around the resolver core.